Jewels Centers For Gerber Daisies

I'm hoping to get a few ideas.... I'm making a 3 tier cake with gerber daisy border on each tier. The theme is "bling" and I would like to use a center for the daisies that look similar to jewels. Daisies will be alternating fusia and silver. I have found pink edible diamonds which will work for silver daisy centers, but can't find silver diamonds for fusia daisies.

Read on a site about using edible silver (I assume luster dust??) on the back of clear diamonds. Anyone ever used an edible silver on back of something to show through??

I have been investigating isomalt gems, which I think are suppose to hold up to humidity??

I found these for sale on the internet (fairly expensive), but I noticed sugarcraft sells a gem mold and has a recipe using edible glitter and isomalt. Seems real easy, but since I have less than 2 weeks, I don't want to have to experiment, once my order arrives.